Craniosynostosis is not contagious. To determine whether a disease is contagious or not, there are three main elements that must be present: the source of infection, the means of transmission and the susceptible person, and craniosynostosis clearly does not meet this definition.
Craniosynostosis is a congenital cranial defect, and although the cause is unknown, it is currently thought to be related to fetal embryonic dysplasia, which can usually be treated surgically and cannot be transmitted or transmitted to others.